Mlodinow and Leukering (2018) wrote a fantastic and informative piece in Colorado Birds about identification of Western and Clark's Grebes along with thorough discussion of hybrids. Not sure if this link will work, but try this:
https://cobirds.org/Publications/ColoradoBirds/InTheScope/84.pdf Adam Vesely Thornton, CO On Sunday, April 11, 2021 at 11:20:26 AM UTC-6 Mark Minner-lee wrote: > If anyone has been out to see the Western and possible Clark’s Grebes at > Stern’s Lake (Boulder County) I’d love some thoughts on how you determined > a Clark’s ID. Additional commentary also welcome from others who would like > to lend their expertise. > > The two grebes I saw both fit Western or Intermediate but not Clark’s. > Flanks on both birds were dark (suggesting Western). Bill color wasn’t > different. Both birds had eyes clearly with the dark supercillium area, > with the suspected Clark’s having some white in the lores. > > Thoughts? > > Regards, > > Mark Minner-lee > Erie, CO > > Sent from my iPhone -- -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/cobirds?hl=en?hl=en * All posts should be signed with the poster's full name and city. Include bird species and location in the subject line when appropriate * Join Colorado Field Ornithologists https://cobirds.org/CFO/Membership/ --- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/407f4ab8-3c63-403a-9247-735707088becn%40googlegroups.com.
